A Water-saving Device for Solar-powered Water Heater

介绍一种用于热水器的节水装置的工作原理,该装置由温度检测系统、PlC控制系统及执行机构(电磁阀)等三部分组成。其节水的功能在于,当用户需要使用热水时,启动节水装置开关,系统自动检测并将原本储存在热水器与水龙头之间的冷水泵回主水管道,直至热水到达出水口时恢复普通使用状态,从而避免将大量冷水放流而造成的水资源浪费。The principle of work of a water-saving device for the solar-powered water heater is presented.The device is made up of three parts: the temperature examination module,the PLC control module and the executive module(two solenoid valves).The saving water process of this device is as follows: when the user needs to use the hot water,open the switch of the device,then the device will make the cold water which between the hot water tank and the tap back to the main pipeline until the hot water gets to the tap.Then the user can use the hot water normally.In this way,lots of water waste can be avoided

Rescaling and Scalar Politics in the‘One Belt, One Road'Strategy

目前,"一带一路"已成为中国的核心发展战略之一。借鉴尺度重构和尺度政治理论,分析"一带一路"战略的内涵、影响和风险。研究发现"一带一路"战略重构了现有的国家角色和地域形式,催生了以跨国基础设施为基础、以资本和经贸合作为支撑的新尺度。该尺度一方面被国际和国内的资本和权力关系不断重构,另一方面也在重构着现有的权力关系和资本积累过程。还从尺度政治视角出发探讨了"一带一路"战略中的风险因素。在国际层面,中国既面临着基于多边国际关系和地方抵抗的尺度上推力量,也面临着基于旧有边界和尺度化表达的尺度下推因素。在国内,"一带一路"战略既面临着地方政府基于政策争夺和地方保护主义产生的重复建设问题,也存在疆独势力等通过国际联系复杂化地方趋势的风险。为了更好地推行"一带一路"战略,中国必须积极应对这些尺度政治的挑战,深入研究尺度政治的机制和破解之道,努力化解海外投资、国际合作和地方治理中的风险。‘One Belt, One Road'(OBOR) was proposed by President Xi Jinping in 2013 when he visited Kazakhstan and Indonesia. It is now the core regional development strategy in China. A series of studies(mainly in Chinese) have been conducted to provide the contextual knowledge or suggestion for this strategy. However,a theoretical examination of OBOR remains at the very superficial level among existing scholarship. This study aims to analyze the nature and impacts of OBOR from the perspective of rescaling and scalar politics,with a balanced consideration on the political geographical mechanisms and potential risks for promoting OBOR. It is argued that OBOR reshapes the roles and territoriality of Chinese state and produces a number of new geographical scales based on construction of international infrastructure, capital flows and trade cooperation. Specifically, the state power is re-territoralized through forming new international organizations and investing in the international infrastructure; the importance of some large cities are also highlighted as the nodes of OBOR. In other words, the inter-national processes are embedded in sub-national regions or new state spaces, confirming the previous theories on‘localization'. The rescaling strategies enable China to gain more influence on Eurasian geo-political and economic processes and more space to accelerate its capital accumulation.This echoes Lefebvre's arguments that the spatial fix of urban growth is based on scalar fixes. Therefore, it is interesting to note that the scale and power relations are mutually constructed. On the one hand, scale is produced and reconstructed by both international and domestic political powers and capitals; on the other hand,the rescaling processes have great impacts on the existing power relations and capital accumulation. The perspective of scalar politics suggests that there are some potential hindrance and risks behind this new initiative.At the international level, China is not only facing complex up-scaling forces related to the multilateral and international relations and local unrests, but also confronting the down-scaling forces based on the existing boundary and scalar discourses. At the domestic level, OBOR may lead to excessive competition, over accumulation and repeated construction due to local protectionism determined by the political promotion system in China. Some potential risks may also be caused by Xinjiang separatists, who can get supports easier than with the further opening of China to the rest of the world in the OBOR strategy. China must cope with these scalar politics actively in order to promote "one belt one road" strategy. This research has much policy implication for Chinese government to smooth the mechanisms of scalar politics on internationalization and reduce the potential risks of oversea investment, inter-national cooperation and regional governance. This aticle also furthers the understanding of scale in human geography by integrating discussions of rescaling and scalar politics from different sub-disciplines.国家自然科学基金项目(40701041;51208444);; 教育部人文社会科学研究基金项目(12YJAGJW007;11YJCZH058);; 中央高校基本科研业务费(20720140519)资助~

Optimized analysis of precision grinding machine bed based on neural network

变形和固有频率是评价精密机床结构刚性的重要参数。为了提高磨床的整体刚性,提出一种利用bP神经网络来优化精密磨床床身结构的方法。以自主开发的高精度平面磨床2Mk1760为研究对象,利用有限元分析软件AnSyS对床身进行静力分析和模态分析。为了减小精密磨床的变形和振动,将部分关键参数作为神经网络的输入,以此预计床身尺寸参数与变形量和固有频率之间的关系,从而获得磨床床身的优化尺寸。分析结果表明,通过神经网络优化后的床身变形量相比初始结构减小了36.51%,而固有频率增加了11.96%。Deformation and inherent frequency are key parameters to evaluate structure rigidity for precision machine tool.In order to improve rigidity for grinding machine,this study proposes a method that using neural network to optimize the structure of precision grinding machine bed.Take precision grinding machine tool( 2MK1760) which is self developed for an example,the static structure and dynamic modal analysis is carried out by using finite element method( ANSYS).In order to alleviate the influence of deformation and vibration on precision grinding machine bed,some parameters are served as input of BP neural work model,which estimate the relationship between deformation and inherent frequency.According to analysis results,an optimization is obtained to determine the dimension of precision grinding machine bed.The results indicate that the deformation after neural network optimization compared with initial structure has decreased by 36.51%,meanwhile,the natural frequency has increased by 11.96%.国家自然科学基金项目(51075343); 福建省自然科学基金项目(2012J05102

厦门市碘缺乏病防治现状与对策

[目的]了解碘缺乏病防治现状,探讨今后防治措施与策略。[方法]采用容量比例概率法抽查学生甲状腺大小、尿碘、盐碘,开展加工厂盐、居民户盐及盐民自用盐的盐碘含量监测。[结果]查2525名8～10岁学生,甲状腺肿大率为3.72%(触诊法),自1995年以来呈逐年下降趋势,合格碘盐食用率89.66%,碘盐覆盖率90.72%,尿碘中位数为246.40μg/L;加工厂盐合格率为99.15%,居民户碘盐覆盖率为95.25%、合格碘盐食用率为94.10%,盐民自供盐10月份后合格碘盐食用率已达到90%以上。[结论]我市继续保持在实现消除碘缺乏病阶段目标,但今后应坚持开展病情监测和坚持防制措施不松懈

Application of Accelerated Solvent Extraction Technique for Analysis of Active Components in Traditional Chinese Medicinal Herbs

以两种药材为研究实例,对加速溶剂萃取法(ASE)在中药材有效成分提取研究中的应用进行了简要介绍。采用正交试验法考察了提取丹参中丹酚酸B的提取条件(萃取温度、静态萃取时间、萃取溶剂以及料液比),确定了较好的实验条件。比较了ASE、水蒸气蒸馏法、超声波提取法及索氏提取法对木香挥发油的提取效果,结果表明ASE对木香挥发油的提取效果最好。The application of accelerated solvent extraction(ASE) technique for the Analysis of active components in traditional Chinese medicinal herbs was introduced by using two kinds of herbs as examples.The conditions including extraction temperature,static extraction time,the ratio of material to solvent and solvent of ASE for extraction of salvianolic acid B in Salvia miltiorrhiza were optimized by orthogonal experiments,and the optimal conditions were obtained.Different extraction methods(ASE,steam distillation,ultrasonic wave and Soxhlet extraction) were used to extract volatile oil in Aucklandia lappa Decne.Results of the comparative experiments indicated that ASE was the most effective method in this case.All the results from these studies demonstrate that ASE is indeed a powerful tool in the preparation of herbal extracts for downstream chromatographic analysis.青岛“2004将才计划”(04-3-JJ-11);; 共建生物医药研发测试中心(LS-05-KJZX-76)资

Analysis of Alkaloids in Coptis chinensis Franch by High Performance Capillary Electrophoresis-Electrospray Ionization Time of Flight Mass Spectrometry

建立了高效毛细管电泳-电喷雾飞行时间质谱联用(HPCE-ESI-TOF/MS)快速定性分析黄连中生物碱类化合物的分析方法.使用未涂层石英毛细管,以50mmol/L乙酸铵-0.5%甲醇溶液(用氨水调至pH=7.2)作为运行缓冲液,分离电压为25kV;鞘液组成为50%甲醇-49.5%水-0.5%乙酸,鞘液流速为4μL/min;质谱选用正离子模式,碰撞电压(Fragmentor)为100V.结果表明,通过各色谱峰紫外光谱和质谱测得精确分子量结果,结合文献,对黄连中7种生物碱进行了鉴定.表明本方法简便、快速,是黄连中生物碱类化合物快速分离、鉴别的有效方法.A new method for the analysis of alkaloids in Coptis chinensis Franch was established by high performance capillary electrophoresis-electrospray ionization time of flight mass spectrometry (HPCE-ESI-TOF/MS). The real samples were separated by an uncoated capillary. 50 mmol/L ammonium acetate containing 0.5% methanol (pH=7.2) was used as the running buffer, and separation voltage was 25 kV. A coaxial sheath flow interface was used as the CE-MS interface, and a 50% methanol-49.5% water- 0.5% acetic acid mixture was used as the sheath liquid with a flow rate of 4 μL/min. The lens voltages in a positive ion mode with a collision induced dissociation (CID) voltage of 100 V were used for ESI-TOF/MS analysis. Seven alkaloids in Coptis chinensis Franch methanol extracts were separated and identified by CE-DAD and CE-ESI-TOF/MS. The coupling of HPCE separation with accurate mass measurement capability of ESI-TOF/MS provides an attractive tool for the identification of alkaloid compounds in Coptis chinensis Franch.国家自然科学基金重点项目(No.20235020);; 青岛“2004将才计划”(No.04-3-JJ-11);; 共建生物医药研发测试中心(No.LS-05-KJZX-76)资助项目

Self-healing of fractured one dimensional brittle nanostructures

Recent experiments have shown that fractured GaAs nanowires can heal spontaneously inside a transmission electron microscope. Here we perform molecular-dynamics simulations to investigate the atomic mechanism of this self-healing process. As the distance between two fracture surfaces becomes less than 1.0 nm, a strong surface attraction is generated by the electrostatic interaction, which results in Ga–As re-bonding at the fracture site and restoration of the nanowire. The results suggest that self-healing might be prevalent in ultrathin one-dimensional nanostructures under near vacuum conditions

Self-healing in fractured GaAs nanowires

Molecular dynamics simulations are performed to investigate a spontaneous self-healing process in fractured GaAs nanowires with a zinc blende structure. The results show that such self-healing can indeed occur via rebonding of Ga and As atoms across the fracture surfaces, but it can be strongly influenced by several factors, including wire size, number of healing cycles, temperature, fracture morphology, oriented attachment and atomic diffusion. For example, it is found that the self-healing capacity is reduced by 46% as the lateral dimension of the wire increases from 2.3 to 9.2 nm, and by 64% after 24 repeated cycles of fracture and healing. Other factors influencing the self-healing behavior are also discussed

Selectivity of biopolymer membranes using HepG2 cells

Bioartificial liver (BAL) system has emerged as an alternative treatment to bridge acute liver failure to either liver transplantation or liver regeneration. One of the main reasons that the efficacy of the current BAL systems was not convincing in clinical trials is attributed to the lack of friendly interface between the membrane and the hepatocytes in liver bioreactor, the core unit of BAL system. Here, we systematically compared the biological responses of hepatosarcoma HepG2 cells seeded on eight, commercially available biocompatible membranes made of acetyl cellulose&ndash;nitrocellulose mixed cellulose (CA&ndash;NC), acetyl cellulose (CA), nylon (JN), polypropylene (PP), nitrocellulose (NC), polyvinylidene fluoride (PVDF), polycarbonate (PC) and polytetrafluoroethylene (PTFE). Physicochemical analysis and mechanical tests indicated that CA, JN and PP membranes yield high adhesivity and reasonable compressive and/or tensile features with friendly surface topography for cell seeding. Cells prefer to adhere on CA, JN, PP or PTFE membranes with high proliferation rate in spheriod-like shape. Actin, albumin and cytokeratin 18 expressions are favorable for cells on CA or PP membrane, whereas protein filtration is consistent among all the eight membranes. These results further the understandings of cell growth, morphology and spreading, as well as protein filtration on distinct membranes in designing a liver bioreactor.</p

Analysis of alkaloids in Coptis chinensis Franch by high performance capillary electrophoresis-electrospray ionization time of flight mass Spectrometry

A new method for the analysis of alkaloids in Coptis chinensis Franch was established by high performance capillary electrophoresis-electrospray ionization time of flight mass spectrometry (HPCE-ESI-TOF/MS). The real samples were separated by an uncoated capillary. 50 mmol/L ammonium acetate containing 0.5% methanol (pH=7.2) was used as the running buffer, and separation voltage was 25 kV. A coaxial sheath flow interface was used as the CE-MS interface, and a 50% methanol-49.5% water- 0.5% acetic acid mixture was used as the sheath liquid with a flow rate of 4 mu L/min. The lens voltages in a positive ion mode with a collision induced dissociation (CID) voltage of 100 V were used for ESI-TOF/MS analysis. Seven alkaloids in Coptis chinensis Franch methanol extracts were separated and identified by CE-DAD and CE-ESI-TOF/MS. The coupling of HPCE separation with accurate mass measurement capability of ESI-TOF/MS provides an attractive tool for the identification of alkaloid compounds in Coptis chinensis Franch